Physiotherapy, or physical therapy, plays an important role in both modern and traditional medical science by incorporating such physical factors as light, electricity, water, cold, heat, and force as well as the principle of exercise therapy into the evaluation and treatment of patients. Electrotherapy, in particular, has been an increasingly popular means of treatment due to its efficacy in relieving pain, developing muscle strength, delaying or preventing muscle atrophy, alleviating muscle spasms, and promoting blood circulation in the skin.
Today, electrotherapy can be carried out in many ways including, for example, by low-frequency electrical stimulation (also known as transcutaneous electrical nerve stimulation, or TENS) or medium-frequency interference waves. TENS uses low-frequency waves whose frequency is lower than 1,000 Hz (generally 0˜100 Hz). A TENS-based electrotherapy device generates electrical nerve stimulation pulses, which are delivered to and thus stimulate a patient's nerves through electrode pads attached to the patient's skin, with a view to killing pain. Medium-frequency interference waves, on the other hand, are medium-frequency waves whose frequency ranges from 1,000 to 1,000,000 Hz; however, as electric waves generate heat at frequencies higher than 10,000 Hz, medium-frequency waves for clinical use are typically within the frequency range from 1,000 to 10,000 Hz. To apply medium-frequency interference waves, two electrode pads with a frequency difference of 0˜100 Hz are generally used (e.g., one at 2,100 Hz and the other at 2,000 Hz). Once the electrode pads are supplied with electricity, medium-frequency waves propagate through the skin and cause electrical interference in tissues deep under the skin, generating low-frequency (0˜100 Hz) waves. Thus, by stimulating muscles with an appropriate electric current, effective treatment can be achieved.
Electrotherapy is especially effective in pain relief (e.g., reducing lower-back pain or pain resulting from degenerative arthritis, rheumatoid arthritis, ligament sprain, tendinitis, or the muscle and fascia pain syndrome), and because of that, many patients add electrotherapy to their treatments to reduce medication (e.g., painkillers). Besides, the electrical stimulation of electrotherapy leads to muscle contraction and therefore helps maintain the mobility of muscles and joints. In the light of this, electrode pads have been used to deliver electric waves of the desired waveforms, amplitudes, and frequencies in order to stimulate a patient's to-be-treated body portions, thereby extending the use of electrotherapy to the treatment of soreness and rehabilitation.
Having worked in the technical field of the present invention for years and paid close attention to related technical development, the inventor of the invention found that the existing electrotherapy devices have two typical issues, namely the sensation of painful stimulation causing discomfort and fear to the User, and neural adaptation (i.e. a change (reduction) over time in the responsiveness of the sensory (neurons) system to a constant stimulus) or accommodation by the User's neural motor system, making the electrotherapy stimulation ineffective for pain relief and to facilitate the enhancement of muscle performance as detailed below:
(1) The issue of painful stimulation causing discomfort to the User: As referring to FIG. 1, the conventional electrotherapy devices are generally configured to output electrical nerve stimulation pulses of a predetermined set of waveforms S1˜S3, in which each waveform S1˜S3 is constructed by a plurality of pulse currents and starts at a constant high level (as in the case of a square wave), meaning a user will suddenly feel relatively strong stimulation, and causing discomfort and painful sensations to the User. This probably explains why some people refuse electrotherapy due to the fear of pain.
(2) The issue of accommodation or neural motor adaptation causing the electrotherapy to be ineffective for pain relief and to facilitate the enhancement of muscle performance: Generally speaking, if the stimulation given to a User during electrotherapy has a constant intensity, waveform, frequency and rest period between each wave, the User's perceived level of intensity of the stimulation and the actual nerve and muscle response to that constant stimulation will reduce with time, even though the intensity of stimulation is actually unchanged. In response to the gradual decline in sensation and neural motor response, the User or the physical therapist performing the electrotherapy would generally increase the intensity or manually change the frequency of the pulse currents applied or manually change the waveform of the pulse currents during the treatment session in order to avoid neural adaptation, but it will be very difficult and inconvenient to the User and the Physical Therapist for performing the additional manual operation of the electrotherapy device in a proper way suitable to the User, if manually changing the intensity, frequency, wave form and rest period duration are not done or not done properly which may lead to an unpleasant and ineffective therapy experience.
The issue to be addressed by the present invention, therefore, is to overcome the aforesaid drawback of the prior art and provide painless and comfortable TENS and EMS stimulations to the User, and to provide preprogrammed modulated TENS and EMS stimulations to the User to avoid neural adaptation for more effective pain relief and enhancement of muscle performance with electrotherapy.